Question

I am new to C#, Windows Forms, and datagridviews. I have a tabbed form: tab 1 displays a datagridview of the exercises table; tab 2 is for adding a new exercise to the table. The exercises table is bound to the datagrid view via test_ExercisesDataSet, vwexercisesBindingSource, vw_ExercisesTableAdapter.

I’m not sure what I need to do to rebind/refresh the binding source in order to get the datagridview to refresh when I switch back to tab 1. If I completely close the form and restart it, I can see the new row in the table.

I’ve seen many examples both on the Web and on StackOverflow but I still don’t understand what I’m doing wrong.

BTW, I’m using Visual Studio 2010.

Any help is appreciated!!

Thanks!

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace testTabbedInterface
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        public string GetConnectionString()
        {
            return connString;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            // TODO: This line of code loads data into the 'test_ExercisesDataSet.vw_exercises' table. You can move, or remove it, as needed.
            this.vw_exercisesTableAdapter.Fill(this.test_ExercisesDataSet.vw_exercises);
            exerciseListDataGridView.DataSource = this.test_ExercisesDataSet.vw_exercises;
        }

        private void InsertExercise(string exerciseName, string exerciseDescription, string exerciseBegin)
        {
            var conn = new SqlConnection(GetConnectionString());
            const string InsertExerciseSql = @"INSERT INTO database.dbo.exercises
                (PK_exerciseUID,
                exerciseName,
                exerciseDescription,
                exerciseBegin,
                exerciseEnd) 
                VALUES 
                (@PK_exerciseUID,
                @exerciseName,
                @exerciseDescription,
                @exerciseBegin,
                NULL)";

            try
            {
                SqlCommand cmd = new SqlCommand(InsertExerciseSql, conn);
                var param = new SqlParameter[4];

                Guid exerciseGUID = Guid.NewGuid();
                param[0] = new SqlParameter("@PK_exerciseUID", exerciseGUID);
                param[1] = new SqlParameter("@exerciseName", exerciseName);
                param[2] = new SqlParameter("@exerciseDescription", exerciseDescription);

                //Convert date(s) to correct format
                DateTime exerciseBeginConverted = Convert.ToDateTime(exerciseBegin);
                param[3] = new SqlParameter("@exerciseBegin", exerciseBeginConverted);

                foreach (SqlParameter t in param)
                {
                    cmd.Parameters.Add(t);
                }

                conn.Open();
                cmd.CommandType = CommandType.Text;
                cmd.ExecuteNonQuery();
                MessageBox.Show("Test/Exercise, " + exerciseName + ", successfully added!", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            catch (SqlException ex)
            {
                string msg = "Error inserting into 'exercises': ";
                msg += ex.Message;
                throw new Exception(msg);
            }
            finally
            {
                conn.Close();
            }
        }

        private void saveExerciseButton_Click(object sender, EventArgs e)
        {
            InsertExercise(exerciseName.Text, exerciseDescription.Text, exerciseBegin.Text);

            this.exerciseListDataGridView.EndEdit();

            tabControl1.SelectTab("testExerciseTab");
        }

        private void addExButton_Click(object sender, EventArgs e)
        {
            tabControl1.SelectTab("exerciseTab");
        }

        private void reloadExListButton_Click(object sender, EventArgs e)
        {
            this.exerciseListDataGridView.Refresh();  
        }
    }
}

Answer 1

Create a LoadDataGridView method:

private void LoadDataGridView() {
    // Fill a DataAdapter using the SelectCommand.
    DataAdapter da = null;

    // The Sql code here

    // In case something fails, bail out of the method.
    if (da == null) return;

    // Clear the DataSource or else you'll get double of everything.
    if (exerciseListDataGridView.DataSource != null) {
        exerciseListDataGridView.DataSource.Clear();
        exerciseListDataGridView.DataSource = null;
    }

    // I'm doing this off the top of my head, you may need to fill a DataSet here.
    exerciseListDataGridView.DataSource = da.DefaultView;

}

Now all you have to do is call that method in both your Form1_Load() and at the end of your InsertExcercise(). If you have to use a DataSet, don’t forget to dispose of the DataAdapter object at the end to conserve resources.